The present invention relates to an arrangement for locking an adjustable safety steering column for motor vehicles which is arranged so that it can be tilted between consoles of the vehicle body in slotted guides, and can be locked with respect to the vehicle body by an adjustable clamping device and pull rod.
From German Patent 902 586, a locking system is known for a tilt steering column for motor vehicles which comprises a clamping device having a pull rod which holds the steering column between two consoles fixed to the vehicle body. For the fixing of the column via a lever, this device requires a relatively large lever pivot path. As a result of the friction disks and the multiple consoles, this device is expensive with respect to its construction and with respect to its mounting. In addition, a clamping device for tiltable steering columns is also known from Great Britain Patent 15 23 638 which, in order to achieve the clamping, has an eccentric element on a lever which is swivelled to the outside for the locking and thus requires a relatively large amount of clearance space for its operation.
An object of the present invention is to provide an arrangement for the locking of an adjustable safety steering column which, while it has short adjusting paths, permits an optimal clamping effect and has a simple compact construction. In addition, in the event of a crash, the arrangement should release the existing locking of the steering column at the vehicle body.
This and other objects are achieved by the present invention which provides an arrangement for locking an adjustable safety steering column for motor vehicles that is arranged to be tiltable and lockable with respect to the vehicle body. The arrangement comprises consoles coupled to the vehicle body which have guiding slots arranged approximately in a vertical plane, the steering column being tiltable between these consoles. An operating lever of the arrangement has an operating rod, while an adjustable clamping device locks the safety column with respect to the vehicle body, and includes an eccentric element arranged in parallel to the axis of the steering column and axially on the operating rod. The arrangement also includes a pull rod having an end side receiving device in which a free end of the operating rod is pivoted, this pull rod extending transversely with respect to the axis of the steering column through said guiding slots.
The present invention has the advantage of having relatively few components which can be manufactured inexpensively and which partially can be mounted to the vehicle body in a preassembled state.
For achieving a locked position or a released position of the steering column in the vehicle, an eccentric element at an operating rod with a handle is used, the operating rod being arranged in parallel to the axis of the steering column and serving both positions by a swivelling of approximately 90.degree.. As a result, an arrangement of the operating rod with respect to the steering column is achieved that is advantageous in achieving a favorable operating position while occupying relatively little space.
The end positions are fixed by stops of a spring so that the locked position as well as the released position are always maintained which contributes to the safety of the adjustment as well as of the clamping position. The returning of the rod of the clamping device from the released position to the locked position is promoted by the stop spring.
A safety device at the end of the clamping bolt provides an unlocking of the steering column in the event of a crash. This unlocking is caused in such a manner that when the steering column is shifted in the driving direction, for example, in the event of a crash as a result of an occupant's impacting on the steering wheel equipped with an airbag, the clamping effect is released in order to permit displacement of the steering system that is as free of lateral forces as possible.
In an embodiment of the present invention, a ball bearing is arranged on the eccentric sleeve to ensure a smooth release of the clamping as well as a smooth locking since the ball bearing can roll on the eccentric sleeve.
The size of the eccentricity defines the clamping effect so that, when the clamping effect is maximal, the largest eccentricity of the sleeve part is directed to the adjacent console.
So that it is possible to hold the steering column during the tilting, a spring-loaded detent pin is provided which, while the driver tilts the steering column into the desired position, holds the steering column for the purpose of locking.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.